This feature has been removed from the Web standards. Though some browsers may still support it, it is in the process of being dropped. Avoid using it and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
Warning: document.registerElement() is deprecated in favor of customElements.define().
This page is not complete.
document.registerElement() method registers a new custom element in the browser and returns a constructor for the new element.
Note: This is an experimental technology. The browser you use it in must support Web Components. See Enabling Web Components in Firefox.
var constructor = document.registerElement(tag-name, options);
- The name of the custom element. The name must contain a dash (-), for example
- options Optional
An object with properties prototype to base the custom element on, and extends, an existing tag to extend. Both of these are optional.
Here is a very simple example:
var Mytag = document.registerElement('my-tag');
Now the new tag is registered in the browser. The
Mytag variable holds a constructor that you can use to create a
my-tag element in the document as follows:
This inserts an empty
my-tag element that will be visible if you use the browser's developer tools. It will not be visible if you use the browser's view source capability. And it won't be visible in the browser unless you add some content to the tag. Here is one way to add content to the new tag:
var mytag = document.getElementsByTagName("my-tag"); mytag.textContent = "I am a my-tag element.";
We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!
|Feature||Chrome||Firefox (Gecko)||Internet Explorer||Opera||Safari|
|Basic support||35||31||No support||25||No support|
|Feature||Android||Firefox Mobile (Gecko)||IE Mobile||Opera Mobile||Safari Mobile|
|Basic support||4.4.4||31||No support||25||No support|
 This API is implemented behind a preference.